Vehicle clearance lamp assembly
BACKGROUND OF THE INVENTION 
     This invention relates to automotive type lamp assemblies and more particularly to clearance type lamps for vehicles where traditionally several lamps are mounted in a row. 
     It is highly desirous in the vehicle industry to have a clearance light assembly that can be quickly and easily installed on a vehicle, quickly and easily serviced should a bulb burn out, and quickly and easily replaced if damaged. While it has been common practice for many years to mount clearance lights on top of cabs and on the back and sides of truck bodies in multiple sequences, it has also been common practice to mount individual lights in a spaced configuration about the vehicle to achieve the desired clearance marking. This has necessitated not only multiple fixtures but multiple connections and has greatly increased the time and cost of installation and servicing. Also, since clearance lights are frequently damaged by various obstructions encountered by the vehicle, the cost of replacement becomes a major concern both from the cost of the fixture and the labor involved. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to improve clearance lighting units for use in motor vehicles, trailers, and the like. It is an object of the present invention to provide a lamp unit for use in clearance lighting in a vehicle that is cheap and economical to manufacture. 
     It is another object of the present invention to provide a clearance light for large over the road vehicles that is simply and easily installed. 
     It is a further object of the present invention to provide a modular clearance light assembly by which multiple lights can be quickly and easily installed with a single electrical connection and physical mounting. 
     It is a still further object of the present invention to provide a clearance light assembly for large vehicles, which can be quickly and easily mounted on the vehicle, and in which the light bulbs can be quickly and easily replaced if they fail. 
     It is yet another object of the present invention to provide a modular clearance lamp assembly that has at least two bulbs in each unit and which is shock mounted within the unit to absorb road and hazard shocks and prolong life. 
     It is yet a further object of the present invention to provide a multiple light clearance lamp assembly which can be mounted on a vehicle with a single electrical connection. 
     These and other objects of the present invention are attained in a particular embodiment of the present invention by means of a modular lamp assembly having a back member with a plurality of lens covers mounted thereon and a corresponding plurality of bulb assemblies resiliently mounted in openings formed in the back member with an electrical bus connecting the bulb assemblies within the over all lamp assembly so that a single electrical connection will activate all bulbs. Simplified fixture mounting, removal and replacement of lens covers and bulbs is achieved by this modular construction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the present invention will be apparent from the following detailed description of the invention which is shown in the accompanying drawings, wherein 
     FIG. 1 is a perspective exploded view of the lamp assembly according to the present invention; 
     FIG. 2 is a perspective view of the back of the assembly of FIG. 1; 
     FIG. 3 is a perspective view of the bulb sub-assemblies removed from the back plate of FIGS. 1 and 2; 
     FIG. 4 is a perspective back view of a single modular lamp according to the present invention; 
     FIG. 5 is a perspective view of the electrical connector plate of the bulb assembly of the present invention; 
     FIG. 6 is a view similar to FIG. 5 of the insulating housing for the connector plate of FIG. 5; 
     FIG. 7 is a perspective view of a pair of assembled housings showing how they can be assembled about a conductor to form a bulb assembly; 
     FIG. 8 is a cross sectional view on line 8--8 of FIG. 4 showing the bulb assembly encapsulated in its mounting base; and 
     FIG. 9 is an end view of a bulb assembly taken on line 9--9 of FIG. 4. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to FIG. 1 there is shown a clearance lamp assembly 10 having three modular bulb and lens cover assemblies 12 which will be described in detail herein. Each assembly 12 includes the back member or portion thereof, a bulb sub-assembly and a lens cover. The individual lens cover 14 can be simply and easily snapped off a base mounting ring 16 on the back plate 18 of the lamp assembly 10. While the lamp assembly 10 is shown herein having 3 individual modular lamp units any desired number can be accommodated with the construction of the present invention. 
     As seen in FIG. 2 each module 12 has positioned therein on the back side of the base 18 a bulb sub-assembly 20 which is connected as will be described herein to a conductor bus having a ground and hot wire which connect with other like bulb sub-assemblies within the overall unit 10 to an end where the ground conductor is connected through one of the mounting fasteners to the vehicle frame. The power or hot side is taken out through one of the end modules for connection to the vehicle electrical system. This is shown in FIG. 3, where the grounding grommet 22 is shown at the left end crimped to the ground wire 24, and the hot wire 26 is shown being brought out in FIG. 2 through a ferrule 28 for connection to the vehicle electrical system. 
     Referring now to FIG. 4 there is shown an individual module 12&#39;, which consists essentially of a single element from FIG. 1 including a lens cover 14&#39; and a bulb module 20, which is identical to the bulb module shown in FIG. 2 except that it is individually connected to the wire 26&#39; and is inside the housing for connection to the mounting bolt that will go through the hole 30 the ground lug 22&#39;. By this modular construction, a clearance light system can be developed having anywhere from 1 to many individual lamp assemblies, each essentially the same as the other, all ganged together and connected by a single electrical connection to the electrical system of the vehicle. 
     To take advantage of this modularity it was essential to develop a simple bulb socket or subassembly system to permit rapid construction of one or more bulb subassemblies to fit the desired lamp assembly configuration. 
     The heart of the bulb subassembly 20 is a conductive connector plate 32 as shown in FIG. 5 which has at one end two pairs of upturned spring fingers 34 that are extended to receive there-between a lamp stem having the electrical contact to the element within the bulb folded back on the surface of the glass stem. At the other end of the plate 32 there are two pairs of upstanding insulation piercing ears 36 bent up at right angles on each side of the plate 32 and spaced apart a distance slightly less than the diameter of the wire to be connected to the bulbs. The inner or adjacent edge 38 of ears 36 are sharpened to cut into wire insulation. 
     As may be seen in FIG. 6 there is shown in phantom lines an insulated wire conductor 24 inserted into the ears 36. The wire 24 is forced down between the ears 36, which due to the sharp edges 38 cut through the insulation and make good electrical contact with the wire 24 running through the conductor. 
     To insulate the conductive plate 32 from other parts of the apparatus and to securely support the conductors 24 and 26 between the upstanding ears 36 there is provided a housing 44 of a nonconducting plastic or other material. Housing 44 includes channel 45 at one end and tab 46 at the other. Channel 45 receives the opposed pairs of spring fingers 34. At the other end hinged tab 46 has a clamping pad 48 extending therefrom which is positioned to overlie the conductor placed between the ears 36 to hold it securely in electrical and mechanical engagement therewith. The hinged tab 46 is folded over plate 32 positioned in the housing 44 and hole 51, in tab 46 is engaged about the stud 50 of housing 44 to hold the pad 48 in tight engagement about a conductor inserted between the ears 36. 
     After a connector plate 32 and housing 44 are assembled about a conductor 24, a similar connector plate and housing are assembled about a second conductor 26 and then the pair is joined together in face to face mating relationship as shown in FIG. 7. This is facilitated by a stud and slot on the back of tab 46 which mate with their counterparts when assembled together in face to face relationship as shown in FIG. 7, each housing 44 has a bail 52 and striker lug 54. Latch bail 52 snaps over and engages the corresponding striker lug 54 on the facing housing sub-assembly. As can be seen in FIG. 6 this secures the two sub-assemblies together to form the lamp receptacles 60 and 62 in the ends of the housing 44. 
     The entire sub-assembly is then positioned in a mold for forming the resilient base 56 about the pair of housings 44 and the respective conductors 24 and 26 as they pass through the housings to form a unitary bulb sub-assembly 20 in which a pair of bulbs can be mounted one on each end of the housings at 60 and 62 and which are connected through the connector plates 32 to the appropriate conductor 24 or 26. Base 56 as may be seen in FIGS. 8 and 9, is completely molded about the housing sub-assembly and the conductors positioned therein to form a resilient compressible base which is adapted to be pushed in a cooperating opening in the back member 18 of a modular lamp assembly. As may be seen in FIGS. 8 and 9 a pair of ribs 58 are provided at the top and bottom of the base 56 so that once it is pushed into the opening in back member 18 it will be retained therein. 
     The base 56 can be made of any elastomeric polymer or other resilient material suitable for providing a shock mounting for the bulb assembly while allowing for the frictional insertion within a properly sized opening in the base 18 so as to permit easy installation and removal for servicing. The molded resin material also securely holds the two housings together at the lower part while the bail 52 and lug 54 hold the housings 44 in tight face to face engagement at the top for insertion of the bulb therein. As may be seen in FIGS. 7, 8, and 9, each half of the sub-assembly forms a connection between one of the conductors and one contact of a bulb when inserted in receptacle 60 or 62. The bulb filament is thus connected between the hot conductor and the ground conductor. 
     It is thus seen that a very simple modular arrangement has been developed in which a pair of bulbs can be quickly and easily inserted in the bulb assembly module which in turn can be simply and easily snapped into the base of the lamp assembly and the lens covers then simply snapped over a retainer ring formed in the base on the exterior side of the base to form a multiple modular lamp assembly for clearance lamp applications or similar types of uses. 
     While the preferred embodiment has been described as clearance lights for large vehicles, obviously this modular construction could be used for both single lights and multiple ganged lights for any type of illuminating application. 
     While this invention has been explained with reference to the structure disclosed herein, it is not confined to the details as set forth and this application is intended to cover any modifications and changes as may come within the scope of the following claims.